patch 8.1.1624: when testing in the GUI may try to run gvim in a terminal

Problem:    When testing in the GUI may try to run gvim in a terminal.
Solution:   Add the -v argument. (Yee Cheng Chin, closes #4605)  Don't skip
            tests that work now.
diff --git a/src/testdir/test_timers.vim b/src/testdir/test_timers.vim
index ee86e2a..42fe415 100644
--- a/src/testdir/test_timers.vim
+++ b/src/testdir/test_timers.vim
@@ -334,7 +334,7 @@
 endfunc
 
 func Test_error_in_timer_callback()
-  if !has('terminal') || has('gui_running')
+  if !has('terminal') || (has('win32') && has('gui_running'))
     throw 'Skipped: cannot run Vim in a terminal window'
   endif
 
@@ -348,7 +348,7 @@
   [CODE]
   call writefile(lines, 'Xtest.vim')
 
-  let buf = term_start(GetVimCommandClean() .. ' -S Xtest.vim', {'term_rows': 8})
+  let buf = term_start(GetVimCommandCleanTerm() .. ' -S Xtest.vim', {'term_rows': 8})
   let job = term_getjob(buf)
   call WaitForAssert({-> assert_notequal('', term_getline(buf, 8))})